Name: fault coordination with reclosers and fuses
Uploaded: 2024-11-21T14:54:34.000Z
Duration: 1 min 26 s
Channel: JoVE

Os religadores automáticos protegem os circuitos de distribuição interrompendo e religando automaticamente um circuito CA de acordo com uma sequência predefinida.
Falhas temporárias, muitas vezes causadas por galhos de árvores ou vida selvagem em circuitos aéreos, são eliminadas por religadores, minimizando a interrupção do serviço e melhorando a experiência do cliente.
No entanto, os religadores podem ser perigosos se entrarem em contato com condutores energizados no nível do solo.
Em circuitos de distribuição radial, a proteção é obtida com uma combinação de fusíveis, religadores e relés de sobrecorrente de retardo. Esses relés, com características inversas, são coordenados com religadores e fusíveis Tipo T.
As configurações do relé priorizam a operação do religador para eliminar faltas antes da ativação do relé.
Se uma falta persistir, o religador trava ou os fusíveis atuam nas faltas a jusante. Após várias religações, os relés de sobrecorrente de retardo de tempo abrem o disjuntor da subestação.
As curvas tempo-corrente representam a coordenação entre os religadores e os fusíveis tipo T.
Os religadores desarmam em classificações mínimas acima da corrente de carga máxima, realizando operações rápidas e atrasadas para eliminar faltas temporárias, permitindo que os fusíveis resolvam faltas permanentes.

religadores e fusíveis

Reclosers and Fuses

Os religadores automáticos de circuito melhoram a proteção dos circuitos de distribuição interrompendo e religando automaticamente um circuito AC de acordo com uma sequência predefinida. Eles gerenciam efetivamente falhas temporárias em linhas de distribuição aéreas, geralmente causadas por galhos de árvores ou animais selvagens, interrompendo brevemente o serviço para melhorar a confiabilidade geral. No entanto, o contato com religadores ou condutores energizados quebrados no solo pode representar sérios riscos.


 Um esquema de proteção abrangente para circuitos de distribuição radial integra fusíveis, religadores e relés de sobrecorrente de retardo de tempo. Esses relés, geralmente caracterizados por uma curva de tempo-corrente extremamente inversa, são projetados para coordenar com religadores e fusíveis tipo T. As configurações do relé priorizam as operações do religador para limpar as falhas antes que os relés sejam ativados. Se a falha persistir, o religador eventualmente trava após várias tentativas, permitindo que os fusíveis tratem das falhas a jusante. Os relés de sobrecorrente de retardo de tempo abrem o disjuntor da subestação após várias operações do religador.


 Essa coordenação é visualizada usando curvas de tempo-corrente. Os fusíveis do tipo T são selecionados com base nas cargas máximas de derivação para garantir a coordenação adequada com os religadores. Os religadores são ajustados com classificações mínimas de disparo com base na corrente máxima de carga, substituindo assim o pickup de carga fria. Eles normalmente realizam duas operações rápidas seguidas por duas retardadas, permitindo que falhas temporárias se auto-limpem e permitindo que os fusíveis a jusante limpem falhas permanentes.


 A proteção eficaz em sistemas radiais depende da coordenação meticulosa de relés de sobrecorrente e de uma compreensão completa do comportamento do sistema sob várias condições de falha. Essa coordenação garante que as falhas sejam isoladas de forma eficiente, minimizando o impacto no sistema e mantendo a confiabilidade. Os religadores e relés digitais modernos aprimoram ainda mais essa coordenação ao fornecer recursos avançados, como monitoramento em tempo real, recursos de comunicação e ajustes de tempo precisos, contribuindo para a estabilidade geral e proteção do sistema de energia.

Religadores e Fusíveis

Os religadores automáticos protegem os circuitos de distribuição interrompendo e religando automaticamente um circuito CA de acordo com uma sequência predefinida.
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Education

JoVE Core

Electrical Engineering

Engenharia Elétrica

Unit 1

Unidade 1

System Protection

Proteção do Sistema

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

fault coordination with reclosers and fuses

Fault coordination with reclosers and fuses helps protect radial distribution circuits. A recloser is an automatic switch that interrupts AC power and then closes again on a preset schedule. This brief outage can clear temporary faults on overhead lines, such as those caused by tree limbs or wildlife, and it can improve overall reliability.

Reclosers and their ground-level hazards also matter. Contact with a recloser or with a broken energized conductor on the ground can be dangerous. That is why protection in distribution systems must be planned so faults are isolated quickly and safely.

A full protection scheme uses fuses, reclosers, and time-delay overcurrent relays. A time-delay overcurrent relay is a relay that waits longer to trip when the fault current is smaller. These relays often use an extremely inverse time-current curve. They are set to let the recloser act first, while still protecting the substation breaker if the fault remains.

Coordination is shown with time-current curves. Type T fuses are chosen from the maximum tap load so they work properly with reclosers. Reclosers are set with minimum trip ratings based on the maximum load current, which helps them override cold load pickup. In many cases, they make two fast operations and then two delayed ones. This gives temporary faults a chance to clear and lets downstream fuses clear permanent faults. If the fault still does not clear, the recloser locks out after several tries, and the overcurrent relay opens the substation breaker after the recloser operations.

Fault Coordination with Reclosers and Fuses

fault-coordination-with-reclosers-and-fuses

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reclosers and fuses

Fault coordination with reclosers and fuses helps protect radial distribution circuits. A recloser is an automatic switch that interrupts AC power and then closes again on a preset schedule. This brief outage can clear temporary faults on overhead lines, such as those caused by tree limbs or wildlife, and it can improve overall reliability. Reclosers and their ground-level hazards also matter. Contact with a recloser or with a broken energized conductor on the ground can be dangerous. That is...

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key terms and concepts

Learn how reclosers, type T fuses, and time-delay overcurrent relays coordinate to clear temporary faults, lock out persistent faults, and protect distribution circuits.

Fault Coordination with Reclosers and Fuses | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

Fault Coordination with Reclosers and Fuses

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